(1) Field of the Invention
The present invention relates generally to acoustic countermeasure devices such as incoming torpedo and sonar countermeasure systems and, more specifically, to apparatus and method for a launchable countermeasure device with the capability to store, select, program, and rapidly deploy any one or a combination of a variety of countermeasure devices.
(2) Description of the Prior Art
While acoustic countermeasure devices have a small cost in comparison to the cost of the submarines, ships and other vessels they protect, nonetheless it would be desirable to further reduce the costs associated with such systems if the overall effectiveness could be maintained and preferably significantly increased. The submarine fleet currently uses at least two separate countermeasure devices in the external six-inch countermeasure launchers including one against sonar systems and one against incoming threat torpedoes. Due to their sealed construction, communication interface is limited so that stored tactical information tends to be difficult to change. For the same reason, testing and maintenance tends to be difficult and time consuming. As acoustic masking systems involve highly specialized tasks as suggested by the following prior art patents, dedicated components, logistics, and software are used in prior art devices. Modifications and upgrades therefore require significant time and cost. The present design uses only a single cable connection that is preferably provided for receiving launch control panel signals prior to deployment in accordance with specifications of the existing CSA MK2 Launcher system. The signals used by the CSA MK2 Launcher system are different from those used by a standard PC such as RS232 and RS422 signal formats. The CSA MK2 Launcher system is not designed to download operational code or provide signal generation updates such as might be tailored to specific threats as would be desirable for installation dockside rather than at the factory. Several of the following patents disclose prior art efforts to provide countermeasure systems for protecting ships and submarines.
U.S. Pat. No. 4,255,797, issued Mar. 10, 1981, to P. L. Stocklin, discloses a sonic attenuation system for directing a beam of sound of sufficient amplitude for inducing a finite amplitude effect in water for interaction with a field of sound to produce intermodulation products. Energy is removed from the sound field in the formation of the intermodulation products resulting in an attenuation of sound in the sound field.
U.S. Pat. No. 5,341,343, issued Aug. 23, 1994, to R. L. Aske, discloses an explosive actuated acoustic device that emits sound to be used in torpedo countermeasures. Numbered devices are delivered over an extended area and sink through the water. The devices are actuated at different times as they sink, to provide sound masking over an extended period of time. The devices also include safety devices which prevents premature actuation from jarring or jolting and from impact with the water.
U.S. Pat. No. 4,184,209, issued Jan. 15, 1980, to R. P. Christ, discloses a towed decoy system adapted to be towed from a towing vessel, an electrically powered noisemaker, an electrical tow cable attached to the noisemaker, a depressor vane, a depressor cable connected to the depressor vane and to the towing vessel, and means interconnecting the depressor cable and the electrical tow cable at a point near the depressor vane. The interconnecting means comprises a pair of cable grips respectively attached at one end to adjacent sections of the electrical tow cable and at the other end to a snatch block movably mounted on the depressor cable thereby providing slack in the electrical tow cable whereby the noisemaker is towed at a depth not less than that of the point of attachment of the snatch block to the depressor cable.
U.S. Pat. No. 4,438,526, issued Mar. 20, 1984, to R. O. Thomalla, discloses a sound masking system for generating background sound. The background sound is automatically adjusted to ambient noise level by adjusting the amplitude of the frequency levels detected.
U.S. Pat. No. 4,473,906, issued Sep. 25, 1984, to Warnaka et al., discloses an active attenuator for the attenuation of a relatively broad band of lower frequency vibration such as sound waves from a given source, by the introduction of canceling vibration having the mirror image amplitude and phase characteristics of the source vibration.
U.S. Pat. No. 5,033,028, issued Jul. 16, 1991, to D. R. Browning, discloses apparatus for overcoming stroke limitations of moving coil reaction-mass vibration dampers by recovering armature stroke displacement. The coil housing is selectively coupled or de-coupled to the vibrating structure. If, when the armature reaches its travel limit, sufficient damping energy has not been applied to the structure, the coil-housing assembly is decoupled from the structure while the armature is pulsed back to its zero displacement position. The housing is then re-coupled to the surface having displaced some distance from its previous location. The process continues until the needed additional damping force is generated.
U.S. Pat. No. 5,117,401, issued May 26, 1992, to P. L. Feintuch, discloses an active adaptive noise cancelling device that inserts delays in the weight update logic of an adaptive filter employed by the canceller to make the filter stable. It has been found that there is a great deal of flexibility regarding the selection of the delay values. This insensitivity permits designing the delays in advance, and not having to adjust them to different situations as they change, thus no longer requiring a training mode. The canceller dramatically reduces the amount of hardware needed to perform active adaptive noise canceling, and eliminates the need for the training mode, which in some applications, including automobiles, for example, can be as objectionable as the noise sources that are to be suppressed.
U.S. Pat. No. 5,394,376, issued Feb. 28, 1995, to Riddle et al., discloses an apparatus for reducing acoustic radiation from an enclosure containing a fluid that includes one or more vibration sensors in communication with surfaces of the enclosure. A control unit uses a reference signal and a summation signal to calculate a cancellation waveform to offset the cause of the detected vibration.
U.S. Pat. No. 4,025,724, issued May 24, 1977, to Davidson, Jr. et al., discloses an array of independent sound cancellation units arranged over a vibrating noise generating surface. Each unit includes an arrangement of acoustic transducers (sensors) positioned adjacent to the surface to obtain an electrical average of the local acoustic noise generated by a predetermined zone of the surface. A projected output signal detected by the sensors is used as a feedback signal along with appropriate time delays to cancel the effect of the projected output signal, and to cancel the effect of the output of other projectors of the array.
In summary, while the prior art shows various acoustic systems and acoustic countermeasure means, the above disclosed prior art does not show a launchable countermeasure device with the capability to store, select, program and rapidly deploy any one or a combination of a variety of countermeasure techniques and devices. The prior art does not disclose a launchable countermeasure device with capability of computer communications apart from those of a launch control panel and which allows for a variety of functions for factory preset loading, built in testing, downloading of operational code including tactical operational parameters, signal generation updates, greatly reduced hardware requirements and costs, reduced control system size, and less cost to produce than the combined costs of prior art sonar and incoming threat countermeasure systems.
Consequently, there remains a need for a system that allows for greatly increased operational flexibility, improved testing ability, reduced maintenance costs and time, and reduced manufacturing costs and time. Those skilled in the art will appreciate the present invention that addresses the above and other problems.
Accordingly, it is an object of the present invention to provide an improved launchable acoustic countermeasure device, method, and system.
It is another object of the present invention to provide a launchable acoustic countermeasure device that can be rapidly deployed to effect a plurality of different countermeasure techniques.
It is yet another object of the present invention to provide a launchable acoustic countermeasure device that can communicate with either a launch control panel for effecting launch and prelaunch commands as well as with a personal computer external to the hull for downloading data, testing, and upgrading.
It is yet another object of the present invention to provide a system interface for increased external hull communication capability and corresponding increased communications within the hull of the sealed countermeasure device.
These and other objects, features, and advantages of the present invention will become apparent from the drawings, the descriptions given herein, and the appended claims.
In accordance with the present invention, a method for effecting a plurality of countermeasure techniques using a launchable countermeasure device is provided that comprises steps such as connecting an external computer to the launchable countermeasure device through an external connector outside of a hull of the launchable countermeasure device. The external computer communicates with an internal countermeasure processor mounted within the hull of the launchable countermeasure device to thereby transfer from the external computer data related to each of the plurality of countermeasure techniques into a memory of the internal countermeasure processing system. The external computer is disconnected from the external connector and a launch control panel (LCP) is connected to the external connector. The launch control panel can be used to select one or more of the plurality of countermeasure techniques and the launchable countermeasure device is deployed to effect the selected one or more countermeasure techniques underwater. For this purpose and/or to effect updates of tactical data, the external computer is connected to the launchable countermeasure device through the external connector outside of a hull of the launchable countermeasure device. An interface is operable for communicating with the internal countermeasure processor selectively through either a system bus or through a standard communications protocol connection depending on whether the launch control panel or the external computer is connected to the external connector.
A field programmable gate array is preferably used in the interface to determine whether the launch control panel or the external computer is connected to the external connector. Preset information may be stored on an interface. The field programmable gate array on the interface is also preferably used for detecting if arming of the launchable countermeasure device has occurred. A commercial bus interface is preferably used for communicating between the internal countermeasure processor and a hovering system and a signal generator system within the launchable countermeasure device.
The launchable acoustic countermeasure device is therefore operable for deployment by a launch control panel and for dockside programming by an external computer. The launch control panel and the external computer produce a respective launch control panel signal and an external computer signal, each having a different signal format.
The launchable acoustic countermeasure device includes a watertight hull with a data bus mounted within the watertight hull. A signal generator is connected to the data bus for producing countermeasure acoustic signals through a transducer. A hovering subsystem is connected to the data bus for controlling water depth and movement of the countermeasure device. The bus controller communicates with the signal generator and the hovering subsystem through the data bus. The internal countermeasure processing system is operable for producing a signal for the signal generator and the hovering subsystem through the bus controller. The field programmable gate array operates to provide status and control signals when the detection circuitry determines the launch control panel is connected to the external connector. The interface operates to transfer external computer signals to the internal countermeasure processor when the detection circuitry determines the external connector is connected to the external computer.
An electronics module physically supports the bus controller, the internal countermeasure processor, and the interface. The electronics module includes an electronics module bus for electrically connecting the bus controller, the internal countermeasure processor, and the interface. An analog switch in the interface is used for transferring the external computer signals to the communications connection of the internal processor. Non-volatile memory for preset storage is provided on the interface. Isolation and signal conversion circuitry on the interface is operable for accepting one or more computer signal formats from the external computer and a different signal format from the launch control panel.
Thus, in operation, the launchable countermeasure device selectively operates in a PC mode for communicating with an internal countermeasure processing system to install or change operational code data in the memory. For this purpose, the launchable countermeasure device is operable for receiving data in RS232/RS422 or other standard communications protocol signal format when in the PC mode. Alternatively, the launchable countermeasure device operates in a launch control panel mode for activating the internal countermeasure processing system to effect one or more of the plurality of countermeasure techniques. The one or more countermeasure techniques include sonar countermeasure techniques and incoming threat countermeasure techniques.
The launchable countermeasure device of the present invention is designed to replace present processing systems for sonar countermeasure systems and incoming torpedo countermeasure systems. The present invention performs all processing functions and operational requirements of both of these systems in a less costly and more flexible manner. Only one production line is now required. Many of the components of the system are commercially available thereby reducing costs. The system can be upgraded largely by software changes rather than hardware changes, which require opening the hull sections of the countermeasure device. By use of the present invention, factory or dockside programming capabilities are available to update threat tailored responses, program executable code, and the new signal generation requirements as they become available. At the same time, the launch control panel can still communicate with the launchable countermeasure device using the original signal structure and protocol of the CSA MK 2 LCP for loading presets, obtaining current status and commanding the launch. Only one logistics path is required and the new system is less bulky than either of the electronics assemblies that have been replaced thereby.